Blue disazo dye.



UNITED STATES PATENT FFLCE.

WALTER VOIGTLANDER-TETZNER, OF LUDWIGSHAFEN, GERMANY, AS SIGNOR TOBADISCHE ANILIN & SODA FABRIK, OF SAME PLACE.

BLUE DISAZO DYE.

SPECIFICATION forming part of Letters Patent No. 682,510, datedSeptember 10, 1901.

Application filed June 19, 1901. Serial No. 65,175- (No specimens.)

To all whom it may concern.-

Be it known that I, WALTER VOIGTLliNDER- TETZNER, a doctor of philosophyand a chemist, a subject of the King of Saxony, residing atLudwigshafen-onthe-Rhine, in the Kingdom of Bavaria, Germany, haveinvented new and useful Improvements in Disazo 001- oring-Matter, ofwhich the following is a specification.

I have discovered that 2-phenyl-amido-5- naphthol-7 -sulfoacid(hereinafter termed phenyl-I-acid is a valuable component for theproduction of substantive azo dyes, and both symmetrical and mixed dyescontaining this component can be readily prepared.

In this application for Letters Patent I wish to claim the mixed azocoloring matter which can be obtained by the combination of onemolecular proportion of tetrazotised dianisidin with one molecularproportion of phenyl- I-acid and one molecular proportion of 1.8amido-naphthol-alpha-sulfoacid.

Phenyl-I-acid (the production of which I do not claim) can be preparedas follows: The parts are by Weight.

Mix together about one hundred and twenty (120) parts of2.5-dihydroxy-naphthalene-7- sulfoacid, five hundred (500) parts of asolution of ammonium sulfite (containing about forty per cent of (NHQ SOand eighty (80) parts of anilin. Stir the mixture thoroughly and heat iton the water bath until the dihydroxy acid has disappeared, or nearlyso, and, in its place, the phenyl-amido-naphthol sulfoacid has beenformed. This is but slightly soluble in cold dilute mineral acids, sothat it separates out on taking test portions, cooling and acidifying.To work up the reaction product add sufficient carbonate of soda to makeit alkaline, distil off the excess of anilin with steam, acidify thealkaline solution with hydrochloric acid, allow the solution to cool,and collect the acid formed by filtering and Washing. It can be purifiedby recrystallization.

The following example will serve to illustrate the nature of myinvention, but the invention is not confined to the example given, norto the conditions therein described. The parts are by Weight.

Example: Convert two hundred and forty four (244) parts of dianisidininto the tetrazo compound in the known manner, and run the tetrazosolution thus obtained into a well cooled solution of three hundred andsixteen (316) parts of phenyl-I-acid in six thousand (6,000) parts ofwater and such an excess of soda that the reaction liquid remainsalkaline the Whole time. Keep cool with ice. As soon as the formation ofthe intermediate product is ended, introduce the solution or suspensionthereof into a solution of two hundred and forty (240) parts of 1.8amidonaphthol-5-sulfoacid in two thousand (2,000) parts of Water and onehundred and ten (110) parts of calcined soda. Salt out the mixedcoloring matter formed with common salt.

In place of 1.8 amido-naphthol-o-sulfoacid in the above example, 1.8amido-naphthol-tsulfoacid can be employed.

My new coloring matter thus obtained, and whose composition can beexpressed by the formula Phenyl-Lacid DianisidinAmido-naphthol-alpha-sulfoacid is soluble in water with ablue color, towhich solution the addition of hydrochloric acid, or caustic soda lye,produces a violet-blue to blue-violet precipitate. In concentratedsulfuric acid (containing about ninety six per cent of H 80 it dissolveswith a blue-green color and on reduction with zinc and dilute causticsoda lye yields a brown-red vat. The coloring matter dyes unmordantedcotton pure blue shades.

Now what I claim is The new coloring matter obtainable by combiningtetrazotised dianisidin with phenyl-I- acid and 1. 8amido-naphthol-alpha-sulfoacid, which dissolves in water with a bluecolor, to which solution the addition of hydrochloric acid or causticsoda lye, produces a violetblue, to blue-violet, precipitate; whichdissolves in concentrated sulfuric acid with a blue-green color, andyields on reduction with zinc and dilute caustic soda lye a brown-redvat, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing Witnesses.

WALTER VOIGTLANDER-TETZNER.

Witnesses:

JOHN L. HEINKE, JACOB ADRIAN.

